body {
    background: linear-gradient(to right, #e0eafc, #cfdef3);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    background: white;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    padding: 2rem;
    width: 100%;
    max-width: 1400px;
    margin: 5rem auto 2rem;
}

.selected-row { background-color: #e2e8f0 !important; }
.add-modal {
    display: none;
    position: fixed;
    max-width: 800px; /* 调整弹窗宽度 */
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    z-index: 1200;
}

/* 背景灰幕 */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    display: none;
}

.btn-submit {
    background: #4facfe;
    color: white;
    padding: 0.75rem;
    border-radius: 10px;
    transition: background 0.3s;
}

.btn-submit:hover {
    background: #00f2fe;
}

#modifyForm .mb-4 {
    margin-bottom: 1.5rem;
}